Method and apparatus for registration and overlay of sensor imagery onto synthetic terrain

Abstract

A method and apparatus for registering sensor imagery onto synthetic terrain is disclosed. The method comprises the steps of accepting a sensor image having sensor image data, registering the sensor image data, orthorectifying the registered sensor image data, calculating overlay data relating the registered and orthorectified sensor image data to geographical references, converting the registered and orthorectified image data into a texture, and draping the texture over synthetic terrain using the overlay data.

1 . A computer implemented method of registering sensor imagery onto synthetic terrain, comprising the steps of:
 (a) accepting a sensor image having sensor image data;   (b) registering the sensor image data;   (c) orthorectifying the registered sensor image data;   (d) calculating overlay data relating the registered and orthorectified sensor image data to geographical references;   (e) converting the registered and orthorectified image data into a texture; and   (f) electronically draping the texture over synthetic terrain using the overlay data to provide a three dimensional terrain rendering.   
   
   
       2 . The method of  claim 1 , wherein step (a) is performed in a sensor manager module by a first processor, steps (b), (c), and (d) are performed in an image registration module by a second processor, and steps (e) and (f) are performed in a graphics processing unit by a third processor. 
   
   
       3 . The method of  claim 2 , wherein the sensor image data includes the image and image metadata, including the location of the sensor generating the sensor image data. 
   
   
       4 . The method of  claim 2 , further comprising the step of generating metadata from the sensor image, and wherein the registered sensor data is orthorectified, and the overlay data is calculated using the generated metadata. 
   
   
       5 . The method of  claim 1 , further comprising the step of rotating the registered and orthorectified image data calculated in step (d) to a North-up orientation before converting the registered and orthorectified image data into a texture in step (e). 
   
   
       6 . The method of  claim 5 , wherein the step of converting the registered and orthorectified image data into a texture comprises the steps of:
 defining a transparent texture sized to the registered and orthorectified sensor image data;   copying the registered and orthorectified image data to the transparent texture to create an imaged texture; and   georegistering the imaged texture.   
   
   
       7 . The method of  claim 1 , wherein the geographical references include:
 a latitude and longitude of a corner of the registered and orthorectified image; and   an elevation of a center of the registered and orthorectified image.   
   
   
       8 . The method of  claim 1 , wherein the sensor image data is provided by a synthetic aperture radar (SAR). 
   
   
       9 . The method of  claim 1 , wherein:
 the step of accepting sensor image data comprises the step of accepting a plurality of sensor images, each having sensor image data;   the step of registering the sensor image data comprises the step of registering the sensor image data from each of the sensor images;   the step of orthorectifying the registered sensor image data comprises the step of orthorectifying the registered sensor image data for each of the sensor images;   the step of calculating overlay data relating the registered and orthorectified sensor image data to geographical references comprises the step of calculating overlay data relating the registered and orthorectified sensor image data to geographical references for each of the sensor images; and   the step of converting the registered and orthorectified image data into a texture comprises the steps of:
 defining a transparent texture sized to cover all of sensor images to be rendered, including more than one of the plurality sensor images; and 
 copying the registered and orthorectified image data from all of the sensor images to be rendered to the transparent texture. 
   
   
   
       10 . An apparatus for registering sensor imagery onto synthetic terrain, comprising:
 a sensor manager module, implemented by a first processor for accepting a sensor image having sensor image data;   an image registration module, implemented by a second processor for registering the sensor image data, for orthorectifying the registered sensor image data, and for calculating overlay data relating the registered and orthorectified sensor image data to geographical references; and   a graphics processing module, implemented by a third processor for converting the registered and orthorectified image data into a texture and for draping the texture over synthetic terrain using the overlay data.   
   
   
       11 . The apparatus of  claim 10 , wherein the sensor image data includes the image and image metadata, including the location of the sensor generating the sensor image data. 
   
   
       12 . The apparatus of  claim 10 , wherein the first processor generates metadata from the sensor image and the second processor orthorectifies the registered sensor image data, and calculates the overlay data relating the registered and orthorectified sensor image data to geographical references using the generated metadata. 
   
   
       13 . The apparatus of  claim 10 , wherein the second processor further rotates the registered and orthorectified image data calculated in step (d) to a North-up orientation before converting the registered and orthorectified image data into a texture. 
   
   
       14 . The apparatus of  claim 13 , wherein the third processor converts the registered and orthorectified image data into a texture by defining a transparent texture sized to the registered and orthorectified sensor image data, copying the registered and orthorectified image data to the texture to create an imaged texture, and georegistering the imaged texture. 
   
   
       15 . The apparatus of  claim 10 , wherein the geographical references include:
 a latitude and longitude of a corner of the registered and orthorectified image; and   an elevation of a center of the registered and orthorectified image.   
   
   
       16 . The apparatus of  claim 10 , wherein the sensor image data is provided by a synthetic aperture radar (SAR). 
   
   
       17 . The apparatus of  claim 10 , wherein:
 the first processor accepts a plurality of sensor images, each having sensor image data;   the second processor registers the sensor image data from each of the sensor images, orthorectifies the registered sensor image data for each of the sensor images, and calculates overlay data relating the registered and orthorectified sensor image data to geographical references for each of the sensor images; and   the third processor converts the registered and orthorectified image data into a texture by defining a transparent texture sized to cover all of sensor images to be rendered including more than one of the plurality sensor images, and copying the registered and orthorectified image data from all of the sensor images to be rendered to the transparent texture.   
   
   
       18 . An apparatus for registering sensor imagery onto synthetic terrain, comprising:
 first means for accepting a sensor image having sensor image data;   second means for registering the sensor image data, for orthorectifying the registered sensor image data, and for calculating overlay data relating the registered and orthorectified sensor image data to geographical references;   third means for converting the registered and orthorectified image data into a texture, and for draping the texture over synthetic terrain using the overlay data; and   wherein the first means, the second means, and the third means are separate and independent processors.   
   
   
       19 . The apparatus of  claim 18 , wherein the sensor image data includes the image and image metadata, including the location of the sensor generating the sensor image data. 
   
   
       20 . The apparatus of  claim 18 , wherein the second means further comprises means for rotating the registered and orthorectified image data to a North-up orientation before converting the registered and orthorectified image data into a texture. 
   
   
       21 . The apparatus of  claim 20 , wherein the means for converting the registered and orthorectified image data into a texture comprises:
 means for defining a transparent texture sized to the registered and orthorectified sensor image data;   means for copying the registered and orthorectified image data to the texture to create an imaged texture; and   means for georegistering the imaged texture.   
   
   
       22 . The apparatus of  claim 21 , wherein the geographical references include:
 a latitude and longitude of a corner of the registered and orthorectified image; and   an elevation of a center of the registered and orthorectified image.   
   
   
       23 . The apparatus of  claim 18 , wherein the sensor image data is provided by a synthetic aperture radar (SAR). 
   
   
       24 . The apparatus of  claim 18 , wherein:
 the means for accepting sensor image data comprises means for accepting a plurality of sensor images, each having sensor image data;   the means for registering the sensor image data comprises means for registering the sensor image data from each of the sensor images;   the means for orthorectifying the registered sensor image data comprises means for orthorectifying the registered sensor image data for each of the sensor images;   the means for calculating overlay data relating the registered and orthorectified sensor image data to geographical references comprises means for calculating overlay data relating the registered and orthorectified sensor image data to geographical references for each of the sensor images; and   the means for converting the registered and orthorectified image data into a texture comprises:
 means for defining a transparent texture sized to cover all of sensor images to be rendered, including more than one of the plurality sensor images; and 
 means for copying the registered and orthorectified image data from all of the sensor images to be rendered to the texture.